Threatened species 'need help' finding cooler homes

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We are familiar with the debate about designer babies - is it now time to discuss "designer nature"? To help species survive climate change, governments should consider transplanting entire ecosystems to suitable regions, says a group of researchers from Australia, the UK and the US.

As temperatures around the world rise, species are being pushed to higher latitudes and altitudes to find places where they can live.

Although some species are able to make this shift on their own, others are held back by human or natural obstacles. Species that are pushed to the top of a mountain for instance are unlikely to move down the side of the mountain, into warmer climes, in order to then migrate closer to the poles.

They say that conservationists need to assess the risk that climate change poses to individual species, the extent to which they will be physically able to move to cooler climes - and if they are not, how feasible it is to relocate them?

'More than aesthetics'

"[To some extent] this already happens, but not in response to climate change. It is certainly physically possible", says Hugh Possingham of the University of Queensland in Australia, one of the authors of the proposal.

Animals as large as elephants have been moved from one national park to another in South Africa in order to manage the growing populations there, he says.

The proposal goes beyond playing with nature as an aesthetic exercise, say the researchers.

"I interpret the term 'designer nature' as more about envisaging a new nature that we like through personal preference where the objective is very human centred," says Possingham. "Our objective is instead to save as many functioning species as possible - where functioning means reasonable population sizes and the potential for future evolution in a 'natural' context."

Disturbed Earth

For co-author Chris Thomas of the University of York, UK, "naturalness" is no longer a major consideration.

"Virtually the entire planet is already manipulated by humans and by altering the world's atmosphere and climate, we are perturbing every ecosystem on Earth," he told New Scientist.

The aim - and what sets such assisted colonisation aside from zoos - is to move species into existing complex ecosystems, and to even transplant whole ecological communities where appropriate, for example by moving fish and invertebrates to artificial coral reefs.

The translocated animals would be "living in a complex natural environment carrying out an ecological function, for instance harbouring parasites, interacting with other species and evolving," says Possingham.

Imminent start

How soon could this happen? Strict legal frameworks would need to be adopted by nations, says Jean-Christophe Vié, deputy chair of the species survival group at the International Union for the Conservation of nature (IUCN), who was not involved with the proposal. That could take between five and 10 years, says Thomas.

But proposal co-author Camille Parmesan of the University of Texas says some species could be moved much sooner.

At a meeting next month, Parmesan intends to propose that the endangered quino checkerspot butterfly, which lives in southern California and northern Mexico be moved northwards.

She says that the urban sprawl of San Diego and Los Angeles makes it difficult for the species to move to cooler habitats on its own.

'Simplistic proposal'

"The butterfly meets all the criteria for assisted migration," she says. "It is suffering from warmer temperatures even where the habitat is still in good shape and has trouble moving north past the urban sprawl of San Diego and Los Angeles."

"It would be easy to move and should not have a negative impact on the wildlife in its new home region."

"History shows that nature needs help and that we have successfully helped it in the past," says Vié. He concedes that wider debate about assisted colonisation needs to be stimulated, but says the current proposal seems simplistic.

"There are all sorts of issues that will arise when you move species which the authors have not addressed," he says. "For instance, in all these places you are going to move species to, there are already species. There is not an infinite amount of space."

Ecosystem havoc

Scientists who battle the ecological problems caused by invasive species are also likely to be concerned by the proposal.

For decades, they have been fighting agents - such as shipping - that move species around the globe to places where they have the potential to wreak ecosystem havoc. But the proposal authors say they do not advocate moving species over geophysical barriers such as oceans.

Vié maintains that assisted colonisation is not a priority for conservation and that climate change is not yet the greatest threat to biodiversity. "The problem," he told New Scientist, "is that there is so far no standardised way of assessing the threat that climate change poses to different species."

His organisation is in the process of addressing this. In October of this year, the IUCN will present the preliminary results of a comprehensive review of climate threats to over 20,000 species of birds, amphibians and corals.

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